I'm pleased with these wheels (wh r550), as they are notably faster than 'normal' wheels at higher speeds (35km/h and up), side winds are not a problem (rather the contrary) and they accelerate rather well. However, the (sub 800 grams) frontwheel is notably less stable than a wheel with 32/36 spokes. Also, the rear wheel will need some truing after a few hundred kilometers, so durability might be an issue.
They're great for training and that's about it. For $250 you get what ya pay for!
If your looking for something more serious I'd take a look at Rolf Prima's!